Double hydrosulfite and method of making same.



UNITED STATES PATENT OFFICE.

MAX BAZLEN, OF LUDVVIGSHAFEN, GERMANY, ASSIGNOR TO THE BADISCHE ANILINAND SODA FABRIK, OF SAME PLACE.

DOUBLE HYDROSULFITE AND METHOD OF MAKING SAME.

SPECIFICATION forming part of Letters Patent No. 662,339, dated November20. 1900.

Application filed May 22', 1900. Serial No. 17,547. (No specimens.)

tain new solid stable and soluble double salts of hydrosulfurous acidcontaining zinc and an alkali---namely, sodium, potassium, or ammonium.They may be obtained by double I decomposition between hydrosulfite ofone of the above-specified metals (including ammonium) and anothersuitable salt (preferably the chlorid) of some other of theabove-specified metals,provided,ofoourse,that in all cases a Zinc salttakes part in the reaction. Suitable salts are the chlorids of all thesemetals and the nitrates and acetates of the alkalies. To produce zincsodium hydrosulfitafor instance, a solution of zinc hydrosulfite may betreated with common salt, or, on the other hand, a sol utiou of sodiumhydrosulfite maybe treated with zinc chlorid, in both cases the samesalt being formed. So far as the nature of the resulting product isconcerned these processes 0 are the equivalents of one another. Thesesalts possess the composition represented by the general formulaZ1'l(M:S O XH O, (M representing an alkaline metal, including ammonium.)

where it appears in a chemical formula to designate an alkali metal,such as sodium or potassium, or an alkali residue, such as ammonium, thecomposition of the zinc sodium hydrosnlfite, for example, correspondingto In order that my new double salts may be obtained in the purecondition and remain stable in the presence of air, I have discoveredthat they must be rapidly freed from 5 moisture and that this is bestattained by washing them after they have been collected on the filterwith acetone or other medium which is easily miscible with water andevaporates readily. If desired, a washing with ether can follow thewashing with acetone,

In the following I will employ M whereby the drying is still moreexpeditiously elfected. Thesameresultcannotbeobtained by drying thesalts in vacuum before such treatment with a volatile compound, as a certain amount of decomposition always seems to take place in this case.

The following examples show how my invention may be carried intopractical effect and my new product obtained:

Example 1-D0uble salt of zinc sodium h'y- 6o drosulfite from a solutionof zinc hyd i'osulfitc.Prcpare zinc-hydrosulfite solution from and givesoif its water of crystallization at 100 to 110 centigrade. It maycontain a small quantity of unchanged zinc hydrosul- 8o lite.

Emdmple 2-Double salt of zinc and sodium hydrosulfizfe from a solutionof sodium hydrosuZfite.Add twenty-two (22) parts,by weight, of solidzinc chlorid to one hundred (100) parts, by volume, of asodium-hydrosulfite solution, (containing about eight to twelve percent. thereof.) The solution becomes warm and the double salt at oncebegins to sepa rate out. Salt out the rest of the double salt remainingin solution by the addition of common salt to the filtrate.

In both these examples the resultant product may with advantage bewashed with acetone until the water adhering to the salt is 5 removed.Instead of acetone ethyl or methyl alcohol or similar bodies easilymiscible with water and sufficiently volatile may be used, and these canfinally be displaced by ether, if desired. In a similar manner otherdouble 10o salts of zinc and alkali hydrosulfite may be obtained.

My new double hydrosulfites occur in the form of a White crystallinebody, which in the dry condition is stable in the presence of air formonths. Their composition is expressed by the general formula Zn(NaS OXH O. (M represents an alkali radical.) O11 heating, the water ofcrystallization is first given off and then sulfurous acid.Indigo-sulfonicacid solution is decolorized by my new prodnot. Thespecified double hydrosulfite which Idesire to claim has all theabove-men tioned generic properties, and its composition is expressed bythe formula Zn(NaS O ).2H O.

What I claim is 1. The process for the production of a doublehydrosulfite of zinc and an alkali which consists in treating zinchydrosulfite with a salt of an alkali, washing the separated productwith a Volatile medium of drying, all substantially as hereinbeforedescribed.

, 2. The process for the production of a double hydrosulfite of zinc andan alkali which consists in treating zinc hydrosulfite with a salt of analkali, all substantially as hereinbefore described. I

3. As a new product the double hydrosulfite ofzinc and an alkali whichhas a chemical composition corresponding to the formula Zn(MS O .xH Oand is stable for months in the presence of air, and which gives ofisulfurous acid when heated without burnlng.

4:. As a new product the compound hydrosulfite of zinc and sodium whichhas a chemical composition corresponding to the formula Zn(NaS O .2H Oand which is stable for months to the presence of air, Which gives offsulfurous acid when heated without burn ing, and which decolorizes asolution of indigo-sulfonic acid.

In testimony whereof I have hereunto set my hand in the presence of twosubscribing witnesses.

MAX BAZ LEN.

